Just in case someone finds this thread when looking for a solution...
I removed the filter lid with Maf still attached (just 3 nuts hold it onto the lower filter housing)
I taped up the entrance and exit to the MAF and then from the bottom of the lid drilled out the seized bolt using a 4mm bit.
I could then break the seized nut off with shaft and remove the retaining brackets and MAF (put those rusty brackets to one side for a good clean up and Hammerite treatment)
Now the lid was separate from the MAF I hit the remnants hard with a drift and hammer, from underneath and that drove out the nut that was encased in the lid and just turning, when the nut came out of the top it brought a chuck of the lid with it, which was actually quite useful.
offered up a coach bolt left over from some fence work, M6 so same size as the standard bits. Cut the bolt down to size, popped a new m6 nut in the lid and them mixed up some epoxy and bonded the nut in, the plastic back on, and then screwed the coach bolt half way in through the new bolt.
filled the void with more resin and then quickly tighten the coach bolt up and cleaned the threads off that showed through the top.
Once its set and the hammerite had dried on the brackets I put back together using shiny new M6 collared nuts and copper slip to try and stop rusting.
looks good as new and totally standard
pics to follow
2015 - Today 159 2.4 JTDm
2012 - Today GTV 3.0 V6 24v
Gone by not forgotten!
2013 - 2015 156 SW 2.4 JTD
2013 - 2013 145 QV Shed for 1 week - RIP
2011 - 2012 Brera S 3.2 V6 number 21/178
2007 - 2011 GTV 3.0 V6 Q2
Last edited by misterchase; 06-04-14 at 17:09.